Top lawmakers overseeing the House Intelligence Committee’s Russia investigation are threatening to subpoena the White House if the administration does not fully comply with the panel’s request to hand over tapes or memos that might exist of conversations between President Donald Trump and former FBI Director James B. Comey.

The White House sent a letter last week to Intelligence ranking Democrat Adam B. Schiff and Republican Rep. K. Michael Conaway, who is leading the probe, that said a series of tweets by Trump indicating he had “no idea” if there were tapes of Comey was the official White House statement on the matter.

That did not satisfy either Conaway or Schiff, who on Thursday sent another letter asking the Trump administration to fully comply with its request or be subject to a subpoena.

“By only referring to the President’s statement, the White House’s letter stops short of clarifying for the committee whether the White House has any responsive recordings, memoranda, or other documents,” the lawmakers wrote.

Conaway told reporters Thursday he wanted the White House to respond “posthaste.”

“Maybe if I wasn’t such a dinosaur, tweets would be OK,” the Texas Republican said.

Schiff said last week he would seek clarity from the administration after Trump tweeted he had “no idea” if tapes of Comey exist and that the president had not recorded conversations with him.

The California Democrat said he would still seek to question witnesses about the existence of any tapes, no matter the response from the White House.

Conaway has taken over the Intelligence Committee’s probe after the panel’s chairman, California GOP Rep. Devin Nunes, said he would step away amid an ethics inquiry that is investigating whether he improperly leaked classified information.